Elementary
by Midniteoil
Summary: With Moriarty inexplicably back in town, Sherlock is forced to delve back into a world he thought he had locked away. Though when Mycroft brings the three Winchester siblings to the UK to consult on the matter, Sherlock's world is thrown further into turmoil. Can he fix the damage he caused the youngest Winchester and save London at the same time? Or is it too late. Sherlock x OFC
1. Travellers

Authors note:

I promise I'll try and update this as much as I can. Please comment where you can and thank you so much for reading.

 **Chapter 1**

Sherlock wasn't accustomed to having people rampaging through his home. Though, rampaging may have been too strong of a word given that they were merely seated in the chairs across from him talking amongst themselves. It was the first Christmas he had had with John and Mary around, and despite all of the loud noises, laughter and garish decorations dotted around the place, he was strangely… happy. A content sort of ease washing over him as he took a seat in his armchair and watched the two newly-weds talking animatedly to Molly. Her interest seemed to wain though and flicker back across to where he sat, the lights catching her light brown irises turning them to a rich, liquid gold.

"Here we go," Mrs Hudson came teetering up the stairs, a tray nestled between her hands, 6 glasses balanced precariously along its length, "homemade eggnog, with one non-alcoholic for our lovely Mrs Watson."

"Ah Mrs Hudson," John rose from his seat, carefully relieving the lady of her burden and placing the tray down on the coffee table, "you're too kind."

She waved him off with a smile and started handing the glasses out to the small group, crossing the room to hand one to Sherlock where he sat watching them.

"Come on Sherlock, join us," John exclaimed, waving him over, an unreadable expression flashing momentarily across his features.

The man waited a moment, remaining perfectly still before standing and pulling the chair across the room a little further, closing off the circle they had created.

"Is your brother coming along Sherlock?" Mrs Hudson asked turning her attention to the young man. John was grateful for the momentary lapse in attention so he could cringe at the alcohol content in his beverage. Mary elicited a chuckle as he set it back down on the table and wiped his mouth.

"As far as I am aware of, yes, though you never can tell with Mycroft," as if on cue the front door clicked shut and the sound of Sherlock's sibling's voice echoed up the stairs.

"Oh Mycroft dear, come on up, we were just talking about you," Mrs Hudson called from her spot upstairs.

Sherlock sucked in a deep breath and took a long sip of his drink, apparently totally immune to the alcohol burning down his oesophagus as he swallowed. John stared at him with barely concealed surprise from across the room. Mycroft and he were not on the greatest of terms to say the least.

"There you all are," the eldest Holmes exclaimed as he stomped up the stairs and into his brother's abode, "sorry I'm running late. I had to pick up something on the way through."

As he stepped through into the welcoming warmth of the room though everyone's attention was on the sound of more people climbing the stairs followed by three rather haggard looking faces appearing in the doorway.

"Wh…" John stood up instantly, his body tense as he glanced from the three newcomers to the older of the Holmes', "Mycroft? Are you going to introduce us?"

Sherlock was already one step ahead though.

"They are the Winchester children; Dean, Sam and Haley," his eyes settled on the three in the doorway, taking in every minute detail about them from the sleepless looks on their faces to the plane cabin crumpled clothing they wore, "they are wanted in the States for countless charges of murder."

Molly swallowed her mouthful of eggnog rather loudly and stared open mouthed at the travellers. "However," Sherlock continued, "they are not the criminals they are made out to be."

Everyone was staring at Sherlock in stunned silence, all except for the three in the doorway, they appeared to be more disinterested with the man's commentary of their lives than anything else.

John was the first to break the silence, "do, uh, do you know these three, Sherlock?"

The eldest Winchester answered with a vehement 'yes' whilst Sherlock spat out 'no' at exactly the same moment. All eyes moved from one man to the other, curiosity evident in the way each of them seemed to be sitting to full attention.

"You'll have to excuse my brother," Sam said with a forced smile, his American accent sounding stronger against the rather proper British accent that the room shared, "he's just tired from the flight. We do know Sherlock, we had the pleasure of running into him some time ago. He, uh, helped us with a case we were working on."

"What case?" Molly asked, her gaze falling to the man across the room.

"It was nothing," Sherlock responded never once looking away from the new comers.

"Sherlock," John's voice had taken on a stern undercurrent, always the soldier, "what's going on?"

"Why are you here?" Sherlock asked, ignoring his companion's question entirely.

"Mycroft asked us to come," Dean replied, raising an eyebrow at the Brit, "apparently you need our help."

Sherlock bristled, his steely green eyes rising to meet his brother's, "don't look at me like that Sherly, these three are the best in this business."

"What business?" John asked, clearly agitated at being ignored.

Sherlock rose to his feet and strode over to the doorway, stopping a mere foot or so from the siblings.

" _What business?!_ " the soldier barked again.

"Nothing!" Sherlock hissed over his shoulder, "There's no business here for them to take part in."

Sam pursed his lips, his hazel eyes matching Sherlock's green ones, "that's not what your brother seems to think."

"He knows nothing about these things. Why you took his word on it is beyond me, though it doesn't surprise me. He can be quite convincing when he wants to be."

The entire room had gone deathly silent as they watched the exchange in the doorway. No one wanted to move in the fear that it would spark some sort of crazed movement from someone and send everything into a barely contained chaos.

"Someone needs to explain what is going on here," Mary exclaimed after a long, uncomfortable silence, "please."

The only one yet to speak was the youngest Winchester, though she seemed to be entirely uncomfortable in the current situation, more so than was to be expected. As soon as Sherlock had made a move from his chair, she had set her gaze permanently on the floor, almost as though she were too scared to risk a glance up at the man in front of them.

"We worked together back home," Sam began, shooting his brother a warning glance, though Dean barely noticed, he was too involved with staring down Sherlock.

"Worked together is a bit of an overstatement," the Brit retorted, "I mostly did everything and you provided the firearms."

"Without us you would have been hound meat you arrogant jackass," Dean bit back.

"Please, I knew what I was up against the entire time," Sherlock retorted, "your little salt circles did nothing to preserve my life."

"I remember them providing a pretty freaking awesome barrier for your sorry ass."

"I was entirely capable of looking after myself you…"

"Enough!" John stepped forward, coming to stand slightly off to the side of his friend, "just, give it a rest would you. It's Christmas, can we not fight about this tomorrow?"

Sherlock glanced to his side, a long sigh escaping his lips, "fine."

John's gaze fell to the three in the doorway, "do you have anywhere to stay?"

Sam shook his head, "no, we were sort of wrangled at the last minute."

"I'll say," Mary exclaimed from her seat, her face instantly reddening as all gazes fell to her, "sorry. I mean, it's Christmas. Shouldn't you be with your family or something?"

A twinge of pain rippled through the siblings. They had never really experienced a Christmas in the way other people had. For the most part it was the same as any other day, there were no decorations hanging from doorways or presents wrapped in bright paper under a tree in their lives. For starters, in order to have those things they needed to have a home, something that none of them had had in far too long. Dean was the one to field the comment, "this is the only family we have. What you see here is pretty much what we have left. So whether we're in America, England or on some island for Christmas, it doesn't matter to us, as long as we're together."

Mary's expression softened slightly, a smile creeping at the edge of her lips.

"Well, you'll have to stay here with us," Mrs Hudson said with a smile, much to Sherlock's grumbled annoyance, "any friend of Sherlock's is welcome in this home. Now sit, I'll fix you each a cup of eggnog."

"They're not my friends," Sherlock whispered under his breath, staring intently down at his hands like a naughty child.

The woman stood, set her glass on the coffee table and shuffled down the stairs to get more glasses. The three exchanged brief glances before John finally stood and offered to grab one of the bags, "Come on, there's plenty of room in my old bedroom, there's 2 singles in there and I'm pretty sure Mrs Hudson has a mattress somewhere downstairs you are welcome to borrow."

Sam handed his little sister's bag to John and quietly followed him down the hallway and out of sight Dean close in tow, making sure to give Sherlock a stern glare as he wandered passed.

As Haley moved inside though Sherlock stood almost instantly, his movement so abrupt that Haley faltered slightly. Both Mary and Molly were watching him with barely concealed surprise as the young girl made her way towards the hallway, sticking as close to the wall as she could, her eyes never once rising to meet his gaze.

"Haley," his voice was gentle as he moved towards her, it was almost as if he were dealing with a wild animal, a soft side to the usually sarcastic man they all knew.

"Don't," she flinched, shook her head slightly and pressed a little closer to the wall.

If it was at all possible, he looked wounded, as if her simple word had inflicted a myriad of pain, "Please Hal."

"Don't!" she finally looked directly at him, her gaze as fierce as her next words, "don't you dare call me that. You don't get to be friendly with me, you don't get to be _anything_ with me."

And before he could say another word to her she had disappeared around the corner and into John's old room, leaving Sherlock standing there pale faced and completely dumbstruck.

Molly raised her eyebrows and scoffed, "Well isn't she just charming."


	2. Debt collector

Authors note:

Please be patient with me if I don't update all too regularly, I am currently in the middle of editing my own novel to be published soon but I will endeavour to update as much as I can.

Thank you so much for reading and please comment where you can.

(PS thanks to PsychoBeachGirl88 for picking up on the Molly/Holly mistake not sure what I was thinking haha!)

 **Chapter 2**

The Winchester's had obligingly stayed up for one glass of the eggnog, though Dean was the only one that could stomach that much alcohol in a short period of time. Sam and Haley had sipped as much as they could manage for an hour or so before excusing themselves to go and grab the mattress from downstairs, have showers and then get some sleep. Though all of that seemed to be in vain for Haley, no amount of clean clothes or boiling hot showers seemed to settle her. She was tired beyond belief, though unlike her brothers who she was certain were asleep before they had even climbed into bed, she just couldn't seem to drift off into that blissful space between worlds. No matter how hard she tried she just couldn't shut her mind down. Maybe it was the prospect of being in England, or maybe it was the sheer vicinity in which she found herself to one Sherlock Holmes, whatever it was, she resigned herself to the simple fact that she wasn't going to get a seconds worth of sleep at any rate. Checking that both Sam and Dean were sound asleep she pulled one of their Dad's old jumpers on over her head, the thick material falling to just above her knees and the arms entirely too long, before slipping out into the cold silence of the apartment beyond. She stood in the hallway a long moment, revelling in the feeling of the bitter iciness on her skin and the lingering smell of eggnog in the air.

She took a few tentative steps forwards, the chill of the wooden floorboards shocking her body into full blown consciousness. Thin streams of silver moonlight filtered in through the windows casting long, eerily dark shadows across the floor. For the briefest of moments as Haley stood stock still in the hallway, she could have sworn she was back in the living room of their childhood home. There was something so hauntingly familiar about the place that Haley wasn't sure whether the chill that coursed up her spine was because of the weather or because of the room itself. She shook herself almost visibly and slipped quietly into the room. As different as England was to America, there were some things that were oddly similar, if not exactly the same. For one the nights seemed to hold the same sort of hollow emptiness as they did in the USA and there was the same bitter cold that crawled through every nook and cranny, forcing its way into every home, every building, wrapping its tendrils around the world in the quietest of ways.

Haley grabbed her laptop from the table where it had been abandoned earlier and settled herself, cross legged into the chair across from where Sherlock had sat a matter of hours earlier. She flicked open the laptop and sat staring at the screen for a long moment, nothing but the whispering of the snow outside keeping her company. After a long moment of silence she meticulously typed in the password, one letter after another ensuring that she took her time. Given that time was something she had so much of at that moment she was in absolutely no hurry to do anything quickly. The first image that popped up on the garishly bright screen was from their childhood, a long lost memory of Haley in her father's arms as a baby, Dean and Sam standing on either side of him with beaming smiles, each holding toy firearms. It was the last photograph from that time where they looked genuinely happy. A matter of days after that their mother was burned to death in their house, triggering the start of a lifetime of running and hunting. A lifetime of sleepless nights and things that go bump in the night.

"Oh Dad," Haley sighed, lifting her head to look across at the vacant chair in front of her, "I think I'm in over my head this time."

"What are you doing up?" Dean's voice made Haley jump, her attention turning to the hallway, "still not sleeping?"

She caught her brother's sleep laden gaze as he shuffled over to the chair opposite her and slumped into it, "I haven't been able to sleep for a long time Dean."

He studied her for a long moment, "Yeah I know. I was hoping the jetlag would put you out though."

To say that Dean Winchester knew his siblings would be an understatement, they were so ingrained in each other's lives that it was almost like they were in his veins, in his mind, in his heart.

"Don't Dean," Haley shook her head slightly, glancing up at his sombre gaze, a stark contrast to the smiling image on her screen, "I don't need to discuss this right now."

Her brother ran an absent hand through his hair, "fine, fine. Whatever Hal, you know everything right? You've got all of this in the bag huh?"

Haley's eyes narrowed, "what the hell is that supposed to mean Dean?"

"It's supposed to mean that since the second Dad died, you seem to be hell bent on either self-destructing or getting yourself killed."

Two pairs of green eyes met across the room, one boiling with barely contained frustration and annoyance and one with a tired sort of despair.

"Like you can talk Dean," she sighed, clicking the laptop closed once again, maybe she was just touchy from the flight, or the lack of sleep, "you were the one that practically signed your own VIP ticket to Hell."

"Hey, I came back didn't I?"

Haley cocked a slender eyebrow involuntarily, "yeah, and at what expense?"

Before Dean had a chance to answer though another voice sang out from the darkness, "Well, well, well, looks like I have the home advantage here little Winchester."

Haley felt a ripple of dread streak up her spine just as her brother's shoulders visibly tensed beneath his shirt.

"Squirrel," the demon stepped forward, his dark features illuminated by the stream of moonlight sweeping in through the window, "where is that dear little Moose of yours?"

"What," Dean practically threw the chair back as he stood and rounded on Crowley, "in the ever loving fuck are you doing here?"

Crowley made a tutting noise and clasped his hands behind his back with a smirk, "such a dirty mouth. Is that any way to treat an ally?"

"Ally?" the three turned to see Sherlock standing in the hallway, Sam a few inches behind, "if you were an ally I imagine they would be far less aggressive towards you."

"Ah Moose," Crowley smiled, totally ignoring Holmes, "there you are."

"Bite me Crowley," Sam spat, ducking passed Sherlock and coming to stand beside his brother, subconsciously shielding their youngest sibling.

"Come now Moose…" the demon cut himself short, his dark, chocolate irises falling on Haley staring fixatedly on her two brothers refusing to look over at the entrance to the hallway, apprehension practically pooling off of her in waves, "what do we have here? Is the baby Winchester… uncomfortable?"

Haley's head snapped up, her gaze hard and her expression fierce as she rose from her seat, "don't."

The man's eyes flickered across to where Sherlock stood and then back to Haley, "could _this_ be the little weasel that threw you to my hounds?"

Haley flinched involuntarily, it almost sounded like there was a hint of disbelief and… anger in the demon's tone. Sherlock's eyelids flickered shut momentarily before fixing on Crowley, "threw her to _your_ hounds?"

Crowley could practically see how Sherlock's mind was piecing things together bit by bit at that moment, "you're…"

"No. I'm not Lucifer, you sad little human," Crowley snarled, "I am however, here to help."

"Help?" the three siblings exclaimed in unison.

"Yes."

"Why?" Dean hissed.

"Because," the demon flashed another pearly grin, "Jim Moriarty has a debt to pay… and I'm here to collect."


	3. Angels

Authors note:

Please be patient with me if I don't update all too regularly, I am currently in the middle of editing my own novel to be published soon but I will endeavour to update as much as I can.

Thank you so much for reading and please comment where you can.

 **Chapter 3**

"What are you talking about?" Sam asked, somewhat aware that the same question was on everyone's lips at that moment.

Crowley yawned and rolled his eyes, "think, Moose, what exactly is it that I _do_?"

Dean's eyebrows pulled together, realisation suddenly hitting him like a sledgehammer, "what deal did he make?"

"Now, now, that's not really your business is it, Dean?" Crowley retorted with a smirk.

"It is when I get dragged halfway across the freaking world to deal with this bullshit."

"Language Squirrel."

"What do you mean he made a 'deal'?" Sherlock interrupted, clearly disinterested in the way the conversation was currently going and growing more agitated by the lack of information he was being given.

"Crowley is a crossroads demon," Sam replied, glancing over at the Brit, "they make deals with people; give them whatever they want."

"And the price?" Sherlock questioned.

"Their soul," Haley replied, never once removing her gaze from the demon. It was the first thing that she had said to Sherlock in front of the boys and definitely didn't go unnoticed by either of them.

"Their soul?" Sherlock scoffed, "interesting concept."

Dean's attention wavered from Crowley momentarily, his green eyes flickering across the room to catch with Sherlock's, he was not in the mood for this, "I know you want someone to ask you why you said that. But it's not going to happen Inspector Gadget. No one here is interested in your theory on the human soul, none of this even has anything to do with you, so how about you just shuffle on back to bed and get your beauty sleep."

"In case you had forgotten," Sherlock stepped forwards, his eyes hooded, "you are in _my_ abode, in _my_ city, this has everything to do with me and if it weren't for me you wouldn't be where you are right now. Without my help you won't get far."

Something inside Sam snapped, "If it weren't for _you,_ we wouldn't even be here. If it weren't for _you_ we would be back at home, as far away from this place as possible and my baby sister wouldn't be heading straight for… "

"Sam," he stopped mid-sentence, the feeling of his little sister's hand on his arm pulling him back to the present moment, "it's not worth it."

The middle child sucked in a deep breath, his hazel eyes still filled with frustration. He wanted Sherlock to know what he had done to Haley, wanted him to see how badly she had been hurt and the backlash that it had caused for all of them.

"While I do love seeing the three of you so out of sorts, I think we have bigger things to concern ourselves with," Crowley had taken a seat in one of the arm chairs by the empty fireplace, one of his legs crossed just so across the other and a look of, somewhat surprisingly, sincerity in his dark eyes.

"True," Dean nodded, his gaze crossing from his two siblings to Sherlock who had found a spot on the floor and was investigating it with the same intensity he would if it were a case, "do you know what exactly it is that Moriarty is planning?"

Crowley shot Dean a sarcastic glare, "really Squirrel?"

"If you're our ally then you should be giving us as much information as possible Crowley," Dean countered.

"If I _had_ more information, I would give it to you," he scoffed, "sadly not every little minion shares their deceitful, snivelling ideas with me."

"So he _is_ a demon then?" Haley asked.

Crowley half shrugged, "it's a little much to expect that someone can shoot themselves in the head and walk away without a scratch isn't it?"

"We've seen weirder things," Dean scowled, "so which demon are we dealing with then?"

A heavy pause slid its way through the room before Crowley finally let out a sigh and standing up, picking at a stray thread on his otherwise immaculate suit jacket, "he's not just any demon. He was one of the greats downstairs. When Jimbo decided to shoot himself in the head, we collected his soul, for a little while, and he was basically a free meat suit."

"So it's not Moriarty at all then?" Haley asked, green eyes curious in the darkness.

"Mostly."

"Who is it then?" Sherlock asked from the other side of the room.

Crowley seemed to change in that moment. He shifted his weight from one foot to the other ever so slightly, but just enough that all four of the humans in that room noticed. Sherlock in particular seemed to pick up on it in a very different way, his mind racing a million miles a second. Piece by piece he put together what had been said, the look of apprehension in the demons eyes, the thick, taut cloud of tension roping its way around the room.

"He's somebody that they know isn't he?" Sherlock said suddenly, his shoulders pulled back and his jaw set.

Crowley cocked an eyebrow lazily at the man, "he's someone that you _all_ know."

"All of us?" Haley could almost visibly see Sam's brain ticking over the information he had been given. He was trying to place who exactly all of them would know. Sherlock had been with them after their Dad had died, he had been with them when the gates of Hell had been opened so it could have been any demon at that stage.

"Yes, all of you," the demon repeated seemingly bored by the discussion.

"Who?" Dean barked, his voice filling the space like a small explosion, loud and clear, his body language equally as charged as that single word.

Crowley seemed to stare straight passed the two boys though, his hooded eyes locking with Haley's, a bitter chill flooding through her veins as she stared back, using every single ounce of her energy to keep his gaze.

"Azazel."

The silence in that room was so loud Haley could almost hear her brothers heartbeats pick up.

"Yellow eyes?" she whispered.

"No," Dean shook his head, "that can't be true. We wasted him. He's long gone. Years ago."

"You should have made sure he was dead…"

"I shot that fucker in the heart! I watched the light go out in his eyes, I _watched_ him _die_! What more did we have to do to make sure he was dead?" Dean was angry. Beyond angry. He was outright furious. That demon had destroyed their lives, had taken their father, their mother. He had torn apart their family and now he was meant to just sit back and be completely okay with the fact that he was suddenly back in town.

"You of all people should know that there is some very powerful magic in this world Dean Winchester," Crowley replied, his voice low and menacing.

"What are you saying?" Sam jumped in.

"It's not every day that someone gets dragged from Hell without our permission is it?"

Haley's head was swimming, she could feel bile rising in the back of her throat like lava. The demon that had torn apart their family was suddenly back in action, free to roam the streets and destroy other people's lives like he had theirs. Just when they thought they could close one chapter in the story of their extremely messy lives, it comes back to haunt them.

"You said you came here to collect on a deal that Moriarty made," Sherlock surged on, seemingly unperturbed by the information he had just received, "if his body has been possessed then his soul isn't there is it correct? What exactly could you be here to collect?"

Crowley glanced across to where Sherlock stood, barely concealed aggravation in his eyes, "he made two deals, snivelling little idiot that he is. I _thought_ I got his soul, whereas Azazel actually did get his body. Of course I didn't know about this second deal of his. If I get a soul then I get the body as well, and I don't like sharing my toys. I also don't like people backing out of their arrangements."

"What do you mean you _thought_ you got his soul?" Sam questioned, aware of the fact that neither one of his siblings was in a position to speak at that moment.

"I had his soul, had it locked up in a nice little box ready for when we decided we could use him. Then your little angel friends decided that they could use Moriarty, and apparently he was thrown back into his body at the same time Azazel made an appearance."

Dean was visibly shaking, his hands were clenched so tightly by his sides that he was starting to lose all feeling in his fingertips. Yellow eyes had taken away their parents, he had destroyed Sammy and ruined their relationship for a very long time. When he had finally been able to sink a bullet into that bastards heart Dean had felt a weight lift off of his chest. He was able to breathe again, he was able to live again. Seemingly against all odds, he had managed to rebuild a relationship with his siblings, he'd gotten back on track, sure they had stumbled through a few things but they had always had each other in the end. Having Yellow Eyes back was a game changer… in a big way.

"Who brought him back?" Dean asked, his voice shaky.

Crowley caught his eyes across the room, "it's been mayhem down there what with the four horsemen and the apocalypse and everything else. No one has been paying much attention to who wanders in and out with which souls."

"Do you have some sort of _idea_ at least?" Dean hissed.

A deathly silence fell across the room, Haley knew exactly what Crowley was going to say before he even said anything. She could feel her stomach tighten, a horrible burning, bitter taste rising in the back of her throat as she slowly sank back onto the edge of the chair, her head falling into her hands as she sucked in a deep breath.

"Zachariah."


End file.
